Your theme is behaving normally. The grey triangles don’t work in Firefox, either.
The triangle simply indicates that you can click the white bar to toggle that particular option. This is because there is a title attribute attached to that triangle (the words that pop up when you hover over it). However, AFAIK, you cannot attach a title attribute to a div (which is what the white bar is), only an inline element.
Note that it doesn’t “Toggle All Options”, but rather “Toggle all option boxes”, because each box contains one or more related options.
I admit, however, that the triangles title attribute is a bit misleading.